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How to Prevent Hydrogen Embrittlement

Hydrogen embrittlement is the process in which hydrogen atoms react with metals. There are two forms: internal and environmental. Internal hydrogen embrittlement occurs when the metal is molten and reacts with hydrogen. Environmental occurs when solid metal absorbs hydrogen. This leads to cracks, blistering and reduced ductility which is the ability of metal to be stretched into wire or very thin sheets. Steps can be taken during the process to avoid hydrogen embrittlement.

Instructions

- 1
  Reduce or avoid hydrogen producing material during the processing of the metal. Certain activities such as acid pickling, electrochemical cleaning, electroplating, dampness in casting molds and humidity in furnaces during the heat treatment can all lead to hydrogen embrittlement. These can include using acid, electrochemical and electroplating materials that are designed to release low levels of hydrogen during processing.
- 2
  Control and remove stresses from the metal prior to processing it. Residual stresses such as additional tensile and compression forces can lead to additional hydrogen reactions within the metal.
- 3
  Bake the metal to remove additional hydrogen. The American Society for Testing and Materials, which sets the international standards for materials, requires metals to be baked at temperatures between 190 and 220 degree Celsius for different amounts of time based on the tensile strength of the metal. Each metal should be baked for between eight and 22 hours.

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